The Citizens suffered fourth-round elimination in the EFL Cup after they fell to a 2-1 defeat in Wednesday's away clash with Tottenham Hotspur.
To compound Man City's misery, Manuel Akanji and Savinho both picked up injuries at the Tottenham Hotspur Stadium.
Akanji was unable to take his place in the starting lineup after he sustained a calf issue in the warm-up, while Savinho was taken off on a stretcher just after the hour mark.
Guardiola revealed after the game that he did not want to risk Akanji and confirmed that Savinho will have to be assessed on Thursday.
Guardiola provides update on Walker, Grealish and De Bruyne
In addition to addressing Akanji and Savinho's injuries, Guardiola also gave a pessimistic update on Walker, Grealish and De Bruyne.
The Man City manager says does not expect any of the trio to return to action before the November international break.
Speaking after the defeat to Spurs, Guardiola told reporters: "Our captain (Walker) is injured. I don't think he or Kevin will be back until after the international break. Jack Grealish as well."
Walker has missed the last four matches after he sustained a knee injury while on international duty with England earlier this month.
De Bruyne is struggling with a groin problem, while Grealish is sidelined with an injury which has kept him out of the last three matches.
Guardiola laments Man City's injury woes
Man City are also without Jeremy Doku and Oscar Bobb, while Ballon d'Or winner Rodri is set to miss the rest of the season with an anterior cruciate ligament injury.
Guardiola has admitted he is dealing with the worst injury crisis of his Man City tenure, claiming he only has "13 outfield players" at his disposal.
The Man City boss said: "I think when we are in trouble, because in nine years I never had this situation with many injuries for many reasons, in this situation, the players step forward more than ever in all they try to do. We have a short time for recovery this week. We have 13 outfield players."
Guardiola's injury-hit side will have to pick themselves up from their EFL Cup exit as they turn their focus to Saturday's Premier League away meeting with Bournemouth.
The Citizens will then face Sporting Lisbon and Brighton & Hove Albion in their final two outings before the international break.